1. Field of the Invention
The present invention relates to a method for preparing pharmaceutical compounds, particularly a method for preparing pharmaceutical compounds by magnetic carbon nanocapsules.
2. Description of Related Art
A carbon nanocapsule is a polyhedron composed of a enclosed multilayer graphite structure, whose diameter ranges from 1 to 100 nm but is usually 30-40 nm. It is able to be stuffed with magnetic metal inside (a carbon nanocapsule stuffed with magnetic metal is referred to as M@CNC hereafter). As to the graphite layer on the shell of a carbon nanocapsule, the central parts are exclusively six-member rings, the corners are composed of five-member rings, and every carbon atom is sp2; the enclosed multilayer graphite structure endows effective protection of the internal metal particles against oxidization and aggregation, allowing magnetism of internal nano metal to be preserved stably. Besides, the surface of the graphite layer shell of the carbon nanocapsule can be chemically modified, making it disperse in a solvent easily, ready to use, and have stronger affinity. Cis-platinum anticancer drug Cisplatin is widely used to fight against cancer, but because the required material, PtCl4, is very expensive, the manufacture costs of Cisplatin-series anticancer drugs have been high, and the price depends on the yield of the method used for preparation. For methods of prior arts, cis-form and trans-form compounds usually coexist in the products, making it uneasy to purify desired cis-form compounds used to prepare drugs, which often leads to low yields. To avoid formation of trans-form compounds, the prior arts usually need extra steps of preparation in order to raise the proportion of cis-compounds.
There are various ways to prepare cisplatin-series anticancer drugs and the analogs thereof. The yields are usually 28-70% with current techniques. The following formulas exemplifies methods of synthesis known in the art:

Yields of Cisplatin synthesized by the above procedures are low because of the occurrence of cis-form compounds, which are capped at 70%. Thus, to improve yields in order to lower the costs of drug manufacturing, developing a novel and cheap method of preparation is necessary.